New to the forum but not to Opae'ula

[Aquarimax]

Back in 2005, I obtained about 35-40 opae'ula from an online seller, and about 7 from one of those tiny, inadequate enclosures. At the time I lived in Hawaii myself--on Oahu where there are relatively few anchialine pools. Though they did not breed for the first 2-3 years, they began breeding in about 2007. I have sold/gifted at least 100 opae'ula to others since then, and currently have about 150-180 of them. Most of them are in a ~3 gallon vase I purchased from Ikea, and I have a 2-gallon tank at work with about 50-60 in it. I don't filter the tanks, and I rarely change the water. They seem to do quite well.
The tank at work currently has at least 2 berried females in it. The larger tank is probably getting too much food, so I've cut that back a bit in hopes of stimulating breeding again. In the larger tank, I have 2 pipipi (nerites) to help with algae...I had one or two in the tank at work, but after a few years, they died, and I have not yet replaced them.

I've always enjoyed my opae'ula, and am looking forward to giving them bigger homes.

I am about to convert a 5.5 gallon and a 10 gallon tank to new homes for my opae'ula. I have been reading here on this forum lately to get some ideas.

I will have a shallow gravel substrate, some piles of lava rock, and pipipi and trumpet snails as tankmates. No filtration. Both tanks will have some illumination. I feed spirulina powder and occasional fish flakes.

I am planning on getting the lava rock at Home Depot, but I am hoping to find the black lava rock, rather than the red, as the opae'ula look better in contrast to the black. Has anyone encountered problems with lava rock from Home Depot, or found better sources of rock?

If you have any tips, observations, or comments, I would welcome them.

[Stalker]

Hello.

Where are you living now?

[Aquarimax]

Hello.

Where are you living now?

In Utah, a few minutes' drive from the Great Salt Lake, where we occasionally catch brine shrimp. Out in the lake, some of them are as red as opae'ula!


Apparently, Home Depots in Utah only carry the red lava. Luckily, I found a landscape stone retailer near my house. I called them today...they'll sell me black lava at 8 cents a pound. I ought to be able to get more than enough for both my 5.5 and 10 gallon tanks for a few bucks, since lava rock is pretty light.

Unfortunately, the pet shop was out of black gravel. I am weighing the merits of gravel vs. sand and black vs. white.
I've found some posts that have helped on this forum.

Any other insights?

[KenCotigirl]

Nice to have new member. My two cents. I went with black in three tanks. I would not do it again. Any debris is obvious and unsightly. I have another tank with white and some black. 80-20?. My last tank has grey tan aragonite sand. Both of these hide debris.

Ken

[Aquarimax]

Nice to have new member. My two cents. I went with black in three tanks. I would not do it again. Any debris is obvious and unsightly. I have another tank with white and some black. 80-20?. My last tank has grey tan aragonite sand. Both of these hide debris.

Ken

Thanks, I'm glad to find a forum where so many people appreciate my interest in opae'ula!

I bought some black gravel today, thinking that, as in an aquarium, debris would sink down into the spaces between the gravel particles, rather than rest on the surface as it does on sand. However, if black gravel is just as bad as black sand, I can always take it back...I haven't put it in the tank yet. Aragonite is a bit more expensive, but not really that bad. Do the red shrimp show up nicely on the aragonite? That is one of my main concerns...

I got plenty of black lava rock in egg to tennis ball sized pieces (it only cost 8 cents a pound at the local landscaping stone store).

[Aquarimax]

I exchanged the black gravel for a 30 lb. bag of oolitic aragonite sand...sort of an off-white tan color.

Looking forward to setting up the two new opae'ula aquaria!

[Aquarimax]

I exchanged the black gravel for a 30 lb. bag of oolitic aragonite sand...sort of an off-white tan color.

Looking forward to setting up the two new opae'ula aquaria!

I put in the aragonite sand today.

In one tank,(the 5.5 gallon) I went further...I put in the water and enough salt mix for a 4:1 fresh to marine ratio,
I then added some malaysian trumpet snails to get the cycle started. They didn't bat an eye at the brackish water.

I will probably finish setting up the other tank tomorrow.

In my 2 gallon tank, there are three berried females...two large females, one with about 15-18 eggs, one with 8-10, and one small female with a single egg.

[Aquarimax]

Both tanks are now set up. The aragonite sand clouded the water a bit, but is already starting to clear.

I gradually increased the salinity over the course of the day in the 5.5 gallon. It should now be about 50% the salinity of seawater, perhaps a bit less. I will test it to make sure.
I will also add a few pieces of algified lava rock from my established shrimp colonies to help get the cycle going, then wait a few weeks.
Luckily, I'll be going on vacation, so the wait won't be too hard.

[KenCotigirl]

Forgot to mention this. A thick layer of substrate not necessary and may cause problems down the road. A half inch should do.

Ken

[Aquarimax]

Forgot to mention this. A thick layer of substrate not necessary and may cause problems down the road. A half inch should do.

Ken

Thank you for the tip on the substrate! I tried to keep it pretty thin...it might be a bit over a 1/2 inch, but I will probably end up siphoning some of it out.

[khai]

Forgot to mention this. A thick layer of substrate not necessary and may cause problems down the road. A half inch should do.

Ken

Can you please explain why it can cause problems?

[KenCotigirl]

Please forgive my unscientific response. The system promoted on this site is a very low/no maintenance system. Basically add food once or twice a month and top off with ro/distalled water as needed. No water changes and no disturbance of substrate. A deep substrate will create anaerobic conditions in the substrate. Even without disturbance a deep substrate will vent gasses detrimental to shrimp.

Ken

[Aquarimax]

Please forgive my unscientific response. The system promoted on this site is a very low/no maintenance system. Basically add food once or twice a month and top off with ro/distalled water as needed. No water changes and no disturbance of substrate. A deep substrate will create anaerobic conditions in the substrate. Even without disturbance a deep substrate will vent gasses detrimental to shrimp.

Ken

The deep substrate creating anoxic/anaerobic conditions makes a lot of sense. Do trumpet snails with their constant burrowing affect that...negatively or positively?
I know that reef aquaria depend at least partly on various organisms (snails, crustaceans, etc) to dig through the substrate and keep it aerated. Do trumpet snails fill a similar niche in opae'ula aquaria?

[KenCotigirl]

Good question. I can say that i have not seen any snails burrowing into or out of the substrate. Not very scientific.

Ken

[Aquarimax]

Good question. I can say that i have not seen any snails burrowing into or out of the substrate. Not very scientific.

Ken

My current opae'ula tanks have nerites, but no trumpet snails. The new tanks have trumpet snails, which I have seen burrow into the substrate. I have had freshwater tanks where I've seen them burrow as well. I am debating whether or not to keep the trumpet snails in the tanks once they are cycled. Since they are parthenogenic, it might be difficult to remove them all, but I could at least keep numbers to a minimum as I have a couple of assassin snails to feed. : )